oscilloscope is the best GSM fult finding Hardware Equipments

[yunaced]

Originally Posted by ichal_spy

here some picture when i training some poeple use osciloscope... just for prove that osciloscope is very important....

yes good but this picture show poor in ESD

[medis]

Yes

It's a good to have all equipment like oscilloscopes,spectrum analyzers,GSM testers.But i cannot imagine phone repair,which cost 50..100EU and equipment,which cost thousand's of EU or more,needed qualification and time spend on this.Cause in most cases ,when this equipment is needed,phone are after water or mechanical damage,which will lead to unrepairable situation.
So,to repair 2..3 phone from 10,it's time wasting.
I agree with those- is needed good brain,expirience,multimeter,ServiceManual,good resolder tools and sometimes easy oscilloscope.


br

[Dave.W]

These photos show exactly that. Oscilloscope makes you "look" proffesional, and means you can charge more money to run a repair course.

But really, it is useful?

Personally, I dont think so.

I use oscilloscope in other areas, when designing circuits or creating test procedures.

Also I have repaired many many phones since < 2001.

Guess how many times I used oscilloscope on GSM board? none.

Your phone is dead? -> connnect on flasher and see error messages.

Your phone has no signal? -> do manual network search, is problem Tx or Rx?

Of course, we know the charge ways, signal ways, keypad ways from simply looking at the circuit board and using 10 years built knowledge working with these devices!

This method is fully tested in a repair centre, there is NO REAL NEED for 'scope!

[Rizal Arsyad Dini]

Originally Posted by Dave.W

These photos show exactly that. Oscilloscope makes you "look" proffesional, and means you can charge more money to run a repair course.

But really, it is useful?

Personally, I dont think so.

I use oscilloscope in other areas, when designing circuits or creating test procedures.

Also I have repaired many many phones since < 2001.

Guess how many times I used oscilloscope on GSM board? none.

Your phone is dead? -> connnect on flasher and see error messages.

Your phone has no signal? -> do manual network search, is problem Tx or Rx?

Of course, we know the charge ways, signal ways, keypad ways from simply looking at the circuit board and using 10 years built knowledge working with these devices!

This method is fully tested in a repair centre, there is NO REAL NEED for 'scope!

sorry sir,,,

im really like this thread cause we can talk each other and hope can be good study about what we discuss here....


I use osciloscope not only to make me look profesional.... but I use it cause i need it....

i have 2 osciloscope and i use it every day specially for Signal and Dead phone.....


Why i use it????

cause we know that all of voltage and data at a phone can be measured....

so if we wanna know an IC is bad or good we have to know that the out put of the IC is correct....

for example,

For Dead Phone in WD2 like 6600, with 1st boot error message at Flasher Box Like UFS, we must measure some indicator that can make our Phone to be 1st boot OK

What is that????

The conditions to make 1st ok when flashing is :


Vio = 1,8 Volt
Vcorea = 1,5 volt
Vana = 2,8 Volt
Vr3 = 2,8 Volt
PURX = 1,8Volt
Sleepx = 1,8 Volt
Sleep Clock = 32,768 Mhz
Rf Clock = 26 Mhz


If all condition above normal our phone must be 1st ok, if still error the problm must be at CPU


In Signal Problem, Im very depended with oscilocope....

Why???

cause in signal problem many indicator that cant measured with Multi tester, but must with osciloscope like :

Rx i / q from Rf Ic to UEM
RF Bus data from CPU to RF ic
Control VCO from Rf Ic to VCO, etc

if one of this not normal, our phone must be NO RX....

How we can see that indicator with multi tester???

how we can analysis a damaged without this measurement????

thats why i use osciloscope... cause its very important to make me sure about a fungtion of some ic... to know its damaged or not...

Not For High Cost, Not For Look Profesional... but to make me easy in working....



Sorry... just for share... and i hope we can support each other...


regards

[calista]

i gree with u bro...

[Rizal Arsyad Dini]

if we have signal problem, we must make sure aboutn what is is broken...

causen signal problem specially RX Problem can be cause by many componen faults.. like RF IC, VCO, CPU, UEM, and Oscilator 26Mhz....

how we know that that ic is damaged?????? of course by make a measurement.... what tool that we use to make it sure??? one of this, and i think the accurate tools is osciloscope and frequensy counter...

with this tool and reading schematic.. we will know the broken component...


regards

[CPUKILLER]

Originally Posted by Dave.W

These photos show exactly that. Oscilloscope makes you "look" proffesional, and means you can charge more money to run a repair course.

But really, it is useful?

Personally, I dont think so.

I use oscilloscope in other areas, when designing circuits or creating test procedures.

Also I have repaired many many phones since < 2001.

Guess how many times I used oscilloscope on GSM board? none.

Your phone is dead? -> connnect on flasher and see error messages.

Your phone has no signal? -> do manual network search, is problem Tx or Rx?

Of course, we know the charge ways, signal ways, keypad ways from simply looking at the circuit board and using 10 years built knowledge working with these devices!

This method is fully tested in a repair centre, there is NO REAL NEED for 'scope!

i do agree with dave.w because there no comparison for practical experiance and oscilloscopes are actually for quantity repair and alignment where we need a particular fault or component problem coming .(by the way quantity here means testing a particular area on a device pcb in say around 100 units per session )what i mean is oscilloscopes are of industrial application only when it comes to mobile phones.

oscilloscopes are good for repairing vcrs ,cd players and cordless phones and ofcourse televisions because of big and many pcbs bieng installed in 1 device thus making it difficult for fault finding and thats where these oscilloscopes are usefull and frequency counters come in handy for cordless phone repair ,so all in all oscilloscopes are not that usefull for gsm phone repair as most of the phones these days have 1 to 3 main chips installed on a single pcb thus making it easy to find the fault on much lesser covered area with components ,and mostly faults are due to broken or dry connections ,and instead of having an oscilloscope as must device , one should invest in a very good rework station with preheaters and digital temp controls and a high quality tipped ,soldering iron for precise soldering --no offence or criticism to anybody its just my experiance and opinion --regards @ all==b.r.=cpukiller

[Rizal Arsyad Dini]

nice explanations...

[medis]

@ ichal_spy

In theory ,You're absolutely right
But practically,today's parts are very good quality,and pcb place are too small to measure signals (or impossible).SEMC even SM are impossible to find.And phones will do not become HW broken without serious reason
In 99% chances of RF problems are mechanical pcb/parts damage (ceramical RX/TX switches,broken bga balls under RF and CPU interfaces...etc)
Sometimes,here are TX PA burn out.
But i remember 3310 phones,in TX 90% case -it were mechanical PA damage (with ceramic pad).In RX case -broken ceramic switch after fall.
I've repaired a lot.Just 1 phone from 10..20 were needed scope

So,good knowledge and experience may replace expensive equipment.
I don't saying,that i do not use scope


br

[Rizal Arsyad Dini]

Not only teory sir.. i have told u that I use it Everyday...

and when i training some technician... i always told them to use osciloscope...

Oh godness....

I use this tools since 2004 until today...

So.. Not only in theory.....

So whay this picture including in Nokia Schematic if not for measurement???



they make us easy with that picture...

but up to u all... i just try to share here.... and i hope we can be better than now...

regards

[Rizal Arsyad Dini]

We can tell one IC Broke if We know the indicator to Prove that component broken....with measurement...

[medis]

Ok,but how many phones comes with such faults in %?Lets say,some phase or frequency errors,for example.I remember some early Samsung's R210 in this case.People with experience knows about what I'm talking.
And how much cost entry level spectrum analyzer?I mean very professional repair level.Now compare with some 6030 phone,which cost now ~20EU,cause not everybody walks with N95 or N85.Lets look at 5310 board RF part for example.How chips are arranged.-most no discret components here,only bga's
I in the near future i see only bga's in the phones, sealed with epoxy

I wanna just say this:doesn't matter equipment You have use-they main goal are HOW do you use it and what are final result.


br

[Rizal Arsyad Dini]

you're right...

exacly i use osciloscope only for Nokia, i can download this schematic easly.... and i just ue it for dead phone and signal problem..

br

[joeyboy07]

for me oscilloscope is the best

[sp@cific]

oscilloscope is the important device for gsm fault finding...........
but its too expansive for general technician